Spoon the yogurt into a pie shell. Spoon dollops of preserves over the yogurt and swirl in with a thin metal spatula or table knife. Cover and freeze about 2 hours or until just firm, but not completely solid. Remove from freezer; uncover. With a sharp knife, score into 8 pie-shaped wedges. Use a knife to make slits in the side of the pan, centering the slits in each wedge using the score marks as guides. Insert a wooden pop stick into each slit. Cover and freeze until firm, about 2 hours more. Remove from freezer; cut through score marks and use scissors to cut away pan.